Facile construction of MoO3@ZIF-8 core-shell nanorods for efficient photoreduction of aqueous Cr (VI)

Zhang, Yifan; Park, Soo‐Jin

doi:10.1016/j.apcatb.2018.08.077

Cited by 278 publications

(66 citation statements)

References 49 publications

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“…01‐075‐1799), suggesting that there were no other impurities like Cu(OH) 2 or CuO in the prepared Cu 2 (OH) 3 NO 3 . Pure Cu 3 (BTC) 2 showed several peaks at 9.5°, 11.7°, 13.5°, 17.5°, 19.1°, 23.0°, and 36.6°, respectively, in accordance with other researches . Peaks corresponding to Cu 2 (OH) 3 NO 3 and Cu 3 (BTC) 2 could be found over Cu 2 (OH) 3 NO 3 @Cu 3 (BTC) 2 sample.…”

Section: Methodssupporting

confidence: 88%

“…However, to the best of our knowledge, there are few researches about the metal oxides@MOFs core‐shell materials used in NH 3 ‐SCR to date. Epitaxial growth is a popular method to prepare metal oxides@MOFs materials such as MoO 3 @ZIF‐8, and Fe 3 O 4 @Cu 3 (BTC) 2 ; however, the surface of firstly prepared metal oxides need to be modified by functional groups in order to form MOFs over metal oxide cores, which is rather complicated, costly, and time consuming. Therefore, it is highly desirable to develop a facile and efficient method for the synthesis of metal oxides@MOFs core‐shell materials.…”

Section: Methodsmentioning

confidence: 99%

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In situ Growth Synthesis of CuO@Cu‐MOFs Core‐shell Materials as Novel Low‐temperature NH₃‐SCR Catalysts

Chen

et al. 2019

ChemCatChem

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Metal oxides@MOFs core-shell materials were developed for selective catalytic reduction of NO x by NH 3 (NH 3 -SCR). A novel CuO@Cu-MOFs core-shell material with CuO as the core and Cu 3 (BTC) 2 as the shell were rationally designed and synthesized by an in situ growth method and used in NH 3 -SCR reaction. The prepared CuO@Cu-MOFs materials combined physicochemical properties of CuO (high NO adsorption stability and excellent surface reducibility) and Cu 3 (BTC) 2 (large specific surface area and abundant acid sites). In addition, the core-shell materials held large amounts of Brønsted acid sites and abundant adsorbed NO x intermediate species, which benefited NH 3 -SCR reaction under low-temperature. Experimental results demonstrated that CuO@Cu-MOFs possessed higher low-temperature catalytic activity than that of pure CuO and Cu 3 (BTC) 2 . Importantly, CuO@Cu-MOFs performed satisfied stability in NH 3 -SCR reaction, which made it to be a potential and promising low-temperature SCR catalyst.Selective catalytic reduction of NO x by NH 3 (NH 3 -SCR) is one of the most popular methods to eliminate NO x from stationary sources. [1][2][3] V 2 O 5 -WO 3 /TiO 2 materials with high catalytic activity in temperature range of 300-400°C have been successfully used in coal-fired power plants for decades. However, the activate temperature of commercial V 2 O 5 -WO 3 /TiO 2 catalysts is too high in comparison to effluent temperature of cement factory, steel manufacturing, and other stationary sources. [4,5] As such, the efficient SCR catalysts which own high activity under low temperatures are highly desired. [6][7][8] Up to now, considerable attention has been focused on transition metal oxides such as Mn-, Ce-, Cu-, and Fe-based materials which demonstrate high activity in NH 3 -SCR at low temperatures; however, the low tolerance to SO 2 limits the application of these metal oxide catalysts in industry. [9][10][11][12] As a consequence, the development of low-temperature catalysts with superior NH 3 -SCR activity and high SO 2 tolerance is a hot topic in NH 3 -SCR.Metal-organic frameworks (MOFs) as newly emerging materials are important and potential materials in heterogeneous catalytic reactions due to their large specific surface areas, high structural diversity, tunable chemical properties, and highly dispersed metal sites. [13] MOFs have been used as new SCR catalysts by a few groups and are thought to be potential alternatives for commercial SCR catalysts. [14] Researchers have found that MIL-100(Fe), [13] Mn-MOF-74, [16] Co/Mn-MOF-74, [17] and Cu-MOF-74 [18] could perform higher activity than that of V 2 O 5 -WO 3 /TiO 2 catalysts at low temperatures (< 200°C). However, the synthesis procedure of MOFs is rather complicated with high energy consumption and the low-temperature SCR activity of MOFs still needs to be improved.A promising approach to enhance the catalytic performance of MOFs is to fabricate the MOFs into core-shell architecture. Recently, metal oxides@MOFs core-shell materials have been used in various c...

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Section: Methodssupporting

confidence: 88%

Section: Methodsmentioning

confidence: 99%

In situ Growth Synthesis of CuO@Cu‐MOFs Core‐shell Materials as Novel Low‐temperature NH₃‐SCR Catalysts

Chen

et al. 2019

ChemCatChem

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“…Apart from the use of decomposing dyes in wastewater, MoO 3 is also effective for photoreduction of aqueous Cr (VI). Very recently, Zhang et al [109] prepared three-dimensional (3D) MoO 3 @ZIF-8 core-shell nanorod composite photocatalysts and studied the Cr (VI) degradation mechanism, which were shown in Figure 8a,b. Compared with the pure ZIF-8 and MoO 3 nanowires, the MoO 3 @ZIF-8 catalysts exhibited superior photocatalytic activity for Cr (VI) reduction under visible light (see Figure 8c).…”

Section: Photodegradation Of Organic Pollutantsmentioning

confidence: 99%

Nanostructured MoO3 for Efficient Energy and Environmental Catalysis

et al. 2019

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This paper mainly focuses on the application of nanostructured MoO 3 materials in both energy and environmental catalysis fields. MoO 3 has wide tunability in bandgap, a unique semiconducting structure, and multiple valence states. Due to the natural advantage, it can be used as a high-activity metal oxide catalyst, can serve as an excellent support material, and provide opportunities to replace noble metal catalysts, thus having broad application prospects in catalysis. Herein, we comprehensively summarize the crystal structure and properties of nanostructured MoO 3 and highlight the recent significant research advancements in energy and environmental catalysis. Several current challenges and perspective research directions based on nanostructured MoO 3 are also discussed.Molecules 2020, 25, 18 2 of 26 applications in energy and environmental catalysis on account of their relatively low cost, high activity, and stability [9][10][11][12].Molybdenum oxide (MoO 3 ), a kind of transition metal oxide with a n-type semiconducting, nontoxic nature and high stability, has attracted a lot of attention. In particular, nanostructured MoO 3 has demonstrated superior properties to bulk MoO 3 , which is successfully employed in rechargeable batteries [13], capacitors [14], photocatalysis [15], electrocatalysis [16], gas sensors [17], and other applications [6]. The extended tunnels between the MoO 6 octahedra in MoO 3 are suitable for insert/de-insert mobile ions, such as H + and Li + , and multiple oxidation states can enable rich redox reactions. Moreover, the superiorities of low cost, chemical stability, high theoretical specific capacity (1117 mA·h/g), and the environmentally friendly nature make nanostructured MoO 3 exceptional electrode materials for rechargeable batteries capacitors [13,18]. MoO 3 has been investigated as the photocatalyst in terms of its anisotropic layered structure for absorbing UV, as well as visible light. Introducing a defect band by H + intercalation or oxygen vacancies can create defect state and decrease MoO 3 bandgap, which effectively increase the photocatalytic activity [15]. Each oxygen atom bonds to only one molybdenum atom of MoO 6 octahedra, and oxygen vacancy generates Mo dangling bond. MoO 3 favors the adsorption of water molecules in oxygen vacancies, which act as electron acceptors and consequently reduce the energy barrier make it highly reactive for electrocatalysis [2,19]. As a good gasochromic material, MoO 3 has efficient positive-ion accommodation and good charge transfer, and it can be used as an optical-based gas sensor. Moreover, relying on the change in the conductance of the oxide-on-gas adsorption/reaction, MoO 3 has been used for NO, NO 2 , CO, H 2 , NH 3 , and other gases [17]. The unique structure strongly affects the performances. Large efforts have been made to obtain nanostructured MoO 3 with appealing properties by engineering multiple synthetic strategies for the applications in various fields. A variety of methods have been developed, including hydrothermal met...

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“…However, using traditional electrodes, the oxidation peaks of these species overlap, making the simultaneous determination impossible [8][9][10][11][12][13]. To overcome this problem, various modified electrodes based on graphene have been developed [5,[14][15][16], since GO exhibits good conductivity, wide potential window, large electrochemical active surface area, relatively inert electrochemistry, and high electrocatalytic activity [17,18].Several nanomaterials has been extensively studied and applied in technological devices such as sensors, due to mainly their novel properties [19][20][21][22][23]. Among them, water-soluble sulfonated graphene [14], chitosan graphene [15], chemically reduced graphene oxide [16,17], and electrochemically reduced graphene oxide (ER-GO) [24] have been developed into modified electrodes.…”

mentioning

confidence: 99%

“…Several nanomaterials has been extensively studied and applied in technological devices such as sensors, due to mainly their novel properties [19][20][21][22][23]. Among them, water-soluble sulfonated graphene [14], chitosan graphene [15], chemically reduced graphene oxide [16,17], and electrochemically reduced graphene oxide (ER-GO) [24] have been developed into modified electrodes.…”

mentioning

confidence: 99%

Hydrogel-Graphene Oxide Nanocomposites as Electrochemical Platform to Simultaneously Determine Dopamine in Presence of Ascorbic Acid Using an Unmodified Glassy Carbon Electrode

et al. 2018

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The detection of dopamine, an important neurotransmitter in the central nervous system, is relevant because low levels of dopamine can cause brain disorders. Here, a novel electrochemical platform made of a hydrogel–graphene oxide nanocomposite was employed to electrochemically determine simultaneously dopamine (DA) and ascorbic acid (AA). Unlike previous work, where the base electrode is modified, the active material (graphene oxide, GO) was dispersed in the hydrogel matrix, making an active nanocomposite where the electrochemical detection occurs. The GO, hydrogel and nanocomposite synthesis is described. Dynamic Light Scattering, UV-visible and FTIR spectroscopies showed that the synthesized GO nanoparticles present 480 nm of diagonal size and a few sheets in height. Moreover, the polymer swelling, the adsorption capacity and the release kinetic of DA and AA were evaluated. The nanocomposite showed lower swelling capacity, higher DA partition coefficient and faster DA release rate than in the hydrogel. The electrochemical measurement proved that both materials can be employed to determine DA and AA. Additionally, the nanocomposite platform allowed the simultaneous determination of both molecules showing two well separated anodic peaks. This result demonstrates the importance of the incorporation of the nanomaterial inside of the hydrogel and proves that the nanocomposite can be used as a platform in an electrochemical device to determinate DA using an unmodified glassy carbon electrode.

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Facile construction of MoO3@ZIF-8 core-shell nanorods for efficient photoreduction of aqueous Cr (VI)

Cited by 278 publications

References 49 publications

In situ Growth Synthesis of CuO@Cu‐MOFs Core‐shell Materials as Novel Low‐temperature NH₃‐SCR Catalysts

In situ Growth Synthesis of CuO@Cu‐MOFs Core‐shell Materials as Novel Low‐temperature NH₃‐SCR Catalysts

Nanostructured MoO3 for Efficient Energy and Environmental Catalysis

Hydrogel-Graphene Oxide Nanocomposites as Electrochemical Platform to Simultaneously Determine Dopamine in Presence of Ascorbic Acid Using an Unmodified Glassy Carbon Electrode

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Facile construction of MoO3@ZIF-8 core-shell nanorods for efficient photoreduction of aqueous Cr (VI)

Cited by 278 publications

References 49 publications

In situ Growth Synthesis of CuO@Cu‐MOFs Core‐shell Materials as Novel Low‐temperature NH3‐SCR Catalysts

In situ Growth Synthesis of CuO@Cu‐MOFs Core‐shell Materials as Novel Low‐temperature NH3‐SCR Catalysts

Nanostructured MoO3 for Efficient Energy and Environmental Catalysis

Hydrogel-Graphene Oxide Nanocomposites as Electrochemical Platform to Simultaneously Determine Dopamine in Presence of Ascorbic Acid Using an Unmodified Glassy Carbon Electrode

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In situ Growth Synthesis of CuO@Cu‐MOFs Core‐shell Materials as Novel Low‐temperature NH₃‐SCR Catalysts

In situ Growth Synthesis of CuO@Cu‐MOFs Core‐shell Materials as Novel Low‐temperature NH₃‐SCR Catalysts